Method and apparatus for varying package volume during fabrication



April 18, 1967 5, ALFRED 3,314,215

METHOD AND APPARATUS FOR VARYING PACKAGE VOLUME DURING FABRICATION Filed Jan. 18, 1965 4 Sheets-Sheet l lhilhg Ill Hu I A... "IMMI- I, 18

INVENTOR.

6724422" B Aznez'p F 5 J BY Apnl 18, 1967 s. B. ALFRED 3,314,215

METHOD AND APPARATUS FOR VARYING PACKAGE VOLUME DURING FABRICATION Filed Jan. 18, 1965 4 SheetsSheet 2 12-- 9 "mini" a A hilt. Al i INVENTOR. STUAET E ALFRED Apnl 18, 1967 ALFRED 3,314,215

METHOD AND APPARATUS FOR VARYING PACKAGE VOLUME DURING FABRICATION Filed Jan. 18, 1965 4 Sheets-Sheet 5 INVENTOR. i 6 701422 3 AZFEZD ATTOE/VE) A ril 18, 1967 METHOD AND APPARATUS FOR VARYING PACKAGE VOLUME DURING FABRICATION Filed Jan. 18, 1965 4 Sheets-Sheet 4 CONTINUOUSLY FORMING SPREADING THE TUBE FLEXIBLE sHEET MATERIAL TO A PREDETERMINED INTO A TUBE DIAMETER SEALING TOGETHER FILLING THE TUBE THE EDGEs OF THE wITH A SEMILIQUID TUBE PRODUCT CUTTING AND CLOSING THE ENDS OF THE FILLED TUBE WEIGHING THE PACKAGE TO FORM A PACKAGE 1N VENTOR. $201122" 3 ALFRED United States Patent ()fiice 3,314,215 Patented Apr. 18, 1967 3 314,215 METHOD AND APFARATUS F012 VARYTNG PACKAGE VOLUME DURING FABRICATION Stuart B. Alfred, Hopkins, Minn., assignor to The Pillsbury Company, Minneapolis, Minn, a corporation of Delaware Filed Jan. 18, 1965, Ser. No. 426,298 9 Claims. (Ci. 53-182) The present invention relates to an apparatus and process for regulating the volume of a fiexible package as it is fabricated. More particularly, the invention is related -to a process and apparatus for continuously regulating the volume of a flexible package of the type which is formed and filled simultaneously.

For a variety of reasons it is highly important in the case of packages formed from a single sheet or laminate consisting of a flexible web of paper, resinous film material, metal foil or the like to provide a predetermined and precisely controlled volume. One reason is the prevention of either an overfilled or underfilled condition. An underfilled package appears loose and irregularly shaped. The overfilled package is characterized by an overstretched condition of the sheet material from which the package is formed. This, of course, is undesirable since it can lead to breakage of the package wall.

Changes in conditions sometimes make it desirable to change the package volume, for example, a change in density of the material which is being packaged owing to a greater or lesser content of moisture or entrained air. The density of the product moreover may change from one batch to the next and may also change from one minute to the next within the same batch. Thus, if a greater amount of air is entrained within the product, its density will decrease. It is, therefore, necessary to increase the volume of the package to meet requirements previously mentioned. In the past, no reliable means has been pro vided for quickly and easily changing the volume of the package during the time the package forming machine is in operation.

While in some packaging operations, it is possible to change the length of the package to regulate package volume, it is often undesirable since the transversed cuts at the end of each package must register with the labels which are :preprinted on the web of package forming material. Accordingly, if one were to lengthen the package by /8 of an inch, following the fabrication of a total of 16 packages, the web would be cut a total of 2 inches toward the supply roll from the point of the web at which the cut should be made to properly register with the printing thereon.

Many attempts have been made previously to overcome at least some of these problems. For example, the patent to Ballard, 2,856,742, provides a guide for a sausage stuffing machine in which a pair of arcuate hooks establish the extent to which the edges of the sausage casing are overlapped. The amount of the overlap cannot, however, be changed as the casings are formed. The patent to Wood, 2,951,322, shows another packaging machine of the general class of which the present invention is concerned. The patent provides a backing consisting of a leaf spring against which a heated sealing wheel presses the film as the seal is formed in order to assure a light pressure which will result in a good heat seal without deforming the package.

The literature discloses numerous other devices and processes'related generally to the subject of the present invention. These references, however, suifer from numerous shortcomings and have been to some extent ineffective in operation. To be entirely satisfactory, the invention must make possible the changing of package volume while the machine is inoperative as well as during the operation. It should enable the package volume to be changed without affecting the length of the package or the cut oil? length at which the machine is set. It should enable very minute changes in package volume to be quickly and accurately made and must, of course, cause no interference with the travel of the film or other flexible sheet material through the package forming apparatus. In addition, it should :provide reproducible results. Thus, the invention should enable the operator to return the apparatus to a selected setting after a change in package volume has been made.

In view of the shortcomings of the prior art it is one object of the present invention to provide an improved apparatus and process for changing the volume of a package during a fabrication and filling operation.

Another object of the invention is the provision of an improved apparatus and process for changing the volume of a package wherein the apparatus can be reliably reset to a previously established volume.

Still another object of the invention is the provision of an improved process and apparatus for regulating the volume of a tubular package formed from a flexible packaging material wherein the volume changing mechanism will not impede the advance of the film through the package forming apparatus.

Another object of the invention is the provision of an improved apparatus for changing the diameter of a package wherein relatively small changes can be reliably made in the volume of the package and a continuous and infinite numb-er of volume settings can be provided. These and other more detailed and specific objects of the invention will become apparent as the description proceeds.

To the accomplishment of the foregoing and related ends, this invention then comprises the features thereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

FIGURE 1 is a perspective view of an apparatus embodying the present invention. I

FIGURE 2 is a left side elevational view of the apparatus of FIGURE 1 on a slightly enlarged scale.

FIGURE 3 is a plan view of the apparatus on the same scale as FIGURE 2.

FIGURE 4 is a front elevational view of the apparatus on the same scale as FIGURES 2 and 3.

FIGURE 5 is a greatly enlarged exploded view of the extrusion nozzle, film guide and package volume regulating mechanism in accordance "with the invention.

FIGURE 6 is a vertical sectional view of the extrusion nozzle and package volume regulating means on the same scale shown in FIGURE 5.

FIGURE 7 is a partial vertical sectional view taken on line 77 of FIGURE 4 but on a larger scale.

FIGURE 8 is a partial front elevational view taken on line 88 of FIGURE 2 illustrating the film feeding and tension regulating mechanism on an enlarged scale relative to FIGURE 2 and FIGURE 9 is a flow chart illustrating a preferred set of steps for performing the .process according to the invention.

The invention will now be described in connection with a machine of the type in which a tube is formed from flexible sheet material and simultaneously cut into sections which are sealed at each end. It will be understood that the invention is described in connection with the specific type of packaging machine by way of example only and is equally applicable to a variety of other package forming machines as will be readily apparent to those skilled in the art. Since the general construction of the packaging machine of this type is well known, it will be described in general terms only. A more detailed description of the general machine construction can be found in Patent No. 2,831,302.

Referring now to FIGURES 1 through 4 there is shown a package forming and filling machine including a supporting base 12 having laterally spaced vertically disposed legs 14, 16, 18 and 20 which are integral with side panels 22 and 24. The front of the base 12 is covered by a removable front panel 26. The upper surface of the base 12 comprise-s a horizontally disposed top wall 28. At the corners of the top wall 28 are rigidly attached four parallel upwardly extending supports such as rods 30, 32, 34 and 36. Rigidly connected to the top of these rods is a platform 38 upon which is mounted a drive means such as a motor 40 that is connected through a speed changer 42 by the provision of a chain 44 or other suitable transmission to a product feeding and metering means such as a pump 46. The pump 46 includes an inlet duct 48 communicatively connected to a supply means such as a hopper 50 as shown in FIGURE 1 of any suitable construction within which product to be packaged is stored. During operation, the motor 40 will drive the speed changer 42, the chain 44 and the pump 46 thereby forcing the product within the storage hopper 50 downwardly through the pump and out through a pump outlet duct 52. For purposes of illustration the product comprises a seiniliquid, thick, pasty amorphous composition such as a dough from which bakery products can be prepared.

Suitably mounted upon the rods 30 and 32 are a pair of laterally extending brackets 54 and 56 between which is rotatably mounted a shaft 58. Upon shaft 58 is a supply roll 60 of flexible sheet material such as film 61 from which a package is to be constructed. A tension control such as a band 62 to which a weight 64 is secured is mounted to engage the outward edge of the roll 60. In operation, the sheet material 61 passes from the roll 60 upwardly into a tension control of a suitable known construction indicated generally at 66. If desired, before entering the tension controls 66 the film can pass through a registry control also of known construction for automatically regulating the position of a label on the printed film.

The film tension control as best seen in FIGURE 8 includes a pair of vertical front and rear walls 70 and 72 between which are mounted four horizontally disposed rolls 74, 76, 78 and 80. One or both of the rolls 74 or 76 can be mounted resiliently to prevent excessive tension on the web 61 during operation. Before passing over the roll 78, web 61 passes over a roll 80 which is mounted upon the lower end of a post 82 extending downwardly from lower surface of the tension control 66. Secured to the tension control 66 by means of pin 84 is a downwardly extending bracket 86 to the lower end of which is fastened a sealing device 88 of suitable construction such as as electrical resistance heater to which current is supplied through conductors 90 and 92.

From the roll 74 the web 61 passes downwardly over the upper edge of a film folding guide 96, out along its upper edge at an oblique angle with respect to the lower edge thereof. Rigidly secured to the lower edge of guide 94 as by welding is a horizontally disposed mounting plate 104 provided with suitable openings 112411 for cap screws and 102 which secure the plate 104 to a platform 98 which is itself rigidly athxed between the lower edges of the plates 70 and 72.

The guide 94 has a spiral shape as seen from above, and includes overlapping free edges 106 and 108 which are on the opposite side thereof from the roll 74. During operation, the guide 94 causes the side edges of the web 61 to assume an overlapped position as shown at 111) in FIGURE 7 to form the web 61 into a tube.

Telescopically fitted within the lower end of the pump outlet duct 52 is a tubular extrusion nozzle 112 which extends downwardly through the center of the guide 94 and is coaxial therewith. The nozzle 112 is open at the lower end of 114. During operation, the product to be packaged is extruded out the lower end 114 of the nozzle 112 as shown at 116 in FIGURE 7. Rigidly secured as by soldering to the upward end of the extrusion nozzle 112 is a collar 116. The nozzle 112 can be removably attached to the outlet nozzle 52 by the provision of a threaded tubular retainer 118 having a centrally directed flange 120 at its lower end constructed to engage the lower surface of the collar 116.

Secured to the upward end of the extrusion nozzle 112 by means of a threaded connection 122 is a package volume control such as a mandrel 124. Rigidly secured to the upward end of the mandrel 124 is a collar 126 which is grasped manually during operation and rotated about a vertical axis when it is desired to change the volume of the packages being produced. The collar 126 is provided with a marker 125. The nozzle 112 is provided with indicia 127 which enables the collar 126 and mandrel 124 to be reset to a selected position.

Removably but rigidly secured to the lower end of the mandrel 124 is a spring adjustment collar 128 having a beveled lower edge 130, the beveled surface being inclined upwardly towards the outward edge thereof. The rigid but removable attachment between the adjustment collar and the mandrel 124 can be provided through the use of a threaded connection 132 cooperating with a deformable washer 134. The collar 128 is made removable so that collars 128 of different sizes can be used as required. Moreover, it is desirable in some instances to make the collar larger in diameter than the inside diameter of the guide 94. The mandrel 124 can therefore not be withdrawn until the collar 128 has been removed.

Mounted to slidably fit over the lower end of the extrusion nozzle 112 and loosely within the lower end of the collar 128 is a tubular spring backup means such as a ring 136 having a horizontally disposed and laterally extending flange 138. Mounted over the ring 136 is a spreading means such as an extensible resilient spring 140. The tube 61a formed from sheet material 61 engages the outside surface of spring 140. The spring 140 is normally in a retracted position shown in solid lines in FIGURE 6 with the inward edge thereof resting against the vertical outside wall of ring 136. When the mandrel 124 is turned in one direction about a vertical axis it will move downwardly on the extrusion nozzle 112 and cause the spring adjustment collar 128 to engage the upper surface of the spring forcing it outwardly and increasing its diameter. The size of the tube 61a formed from the web 61 will increase correspondingly in diameter thereby increasing the diameter of the packages formed in the tube. Where the spring 140 is reduced in diameter the tube 61a will decrease correspondingly due to the tendency for the sheet 61 to assume a small diameter when passing through guide 94.

Positioned beneath the backup ring 136 are a pair of vertically spaced rings 142 and 144 secured rigidly to the upper and lower ends of a vertically disposed connecting bar 146. The rings 142, 144 and the bar 146 are secured to the extrusion nozzle 112 by means of set screws 148 and 15!). The ring 142 supports the ring 136 in position and the bar 146 underlies the sealing means 88.

The overlapped edges 110 of the tube 61a pass between the bar 146 and the sealing means 88. Since the sealing means is located immediately down stream of the spring 14:), the tube 61:: is sealed at the diameter set thereby. The spring 140 can be thought of as a spreading element and the collar 128 can be thought of as a means for moving the spreading element outwardly. The resiliency of the spring 140 provides a means for yieldably biasing the spring itself inwardly.

The tube 61a which is thus formed and filled with a product 116 as shown in FIGURE 7 passes downwardly between a pair of parallel and horizontally disposed draw rolls 150 and 152 supported for rotation upon a housing 154 which is itself mounted upon a pair of arms 156 and 158 that are secured at their outward ends to the rods 30, 32, 34 and 36 respectively. A suitable drive means such as a motor 160 is mounted upon the housing 154 and is operatively connected to the draw rolls 150 and 152 for driving the same.

Below the draw rolls as seen in FIGURE 1 are provided a pair of cooperating horizontally disposed collapsing rolls 164 and 166 which are moved toward each other periodically by a suitable drive (not shown) so as to reduce the thickness of the tube at the point at which a cut off and end seal is to be made. Mounted below the collapsing mechanism is a cut off and end sealing mechanism 168 of a suitable known construction. The mechanism 168 receives a closure material such as Wire from coils 170 and 172. During operation, the mechanism 168 severs the packages 170 (FIG. 1) from one another and crimps the wire from one of coils 170 or 172 adjacent the cut ends thereof. The packages 170 are then discharged through a chute 172. In order to prevent relative movement between the tube 61a and the mechanism 168, the latter is supported on vertically disposed posts 174 which are slidably mounted within sleeves 176. The posts 174 are connected to a suitable drive means (not shown) within the base 12 and are reciprocated along a vertical axis during operation. Controls for various parts of the machine are provided in a cabinet 178. Since the film feeding mechanism, product feed and metering pump, draw rolls and cutoff and end sealing mechanism are all well known they will not be described in further detail herein. Moreover, it is to be understood that the present invention can be applied to a variety of packaging machines wherein a tube of flexible packaging material is formed and is described in connection with the specific apparatus herein by way of example only.

The operation of the apparatus will now be described in connection with the filling of packages formed from a heat sealable polyester film with a cookie dough. It will be assumed first that the storage hopper 50 is filled with a dough, that the pump 46 is operating at a predetermined and selected speed and that the drawdown rolls are running. It will also be assumed that the compression rolls 164 and 166 are operated periodically to remove the dough from the area of the package which are to be sealed and the cutting and closing mechanism 168 is in operation. It is, of course, well known that dough compositions of the type described include a mixture of sugar, flour, shortening, flavoring, seasoning, moisture and a leavening system. The dough is ordinarily put up in a package 170 having a diameter of from about 1 to 3 inches and a length of about 6 to 12 inches. It has been found that the density of dough material of this type varies from one batch to another and sometimes from one portion of a batch to another. As a result, the tube 61a can become either slack filled or too tightly stretched. If the packages 170 are excessively slack, the operator merely turns the collar 126 in a direction adapted to raise the mandrel 124. This allows the spring 140 to contract and decrease in diameter as such from above. Since the film tends to assume a smaller diameter than the horizontal diameter of the spring 140 the width of overlap 110 will increase and the diameter of the tube 61a will decrease. The packages are cut at a constant length. As a result, their volume will be reduced and the packages will become more tightly packed.

On the other hand, if the packages 170 are filled too tightly due to a decrease in product density, the collar 126 and the mandrel 124 are turned in the opposite direction so as to lower the mandrel and spring adjustment collar 128. This in turn expands the spring 140 and the tube 61a. The amount of film which is overlapped at 110 will thus be decreased and the seal produced on the overlapping edges by the sealing means will be closer to the free edges thereof.

The process according to the present invention will now be described with particular reference to FIGURE 9. As described in FIGURE 9, the process is begun by continuously forming a flexible sheet material into a tube with the edges of the tube lying overlapping abutting relationship. The next step of the process is to spread the inside of the tube to a predetermined diameter. After the tube has been formed and spread to a predetermined diameter, it is sealed longitudinally at the point where the edges thereof are in overlapping abutting relationship. The tube is then filled with a product which is to be contained therein. This product will ordinarily be amorphous and viscous semi-liquid material. In the next step of the process the volume of the package is measured or estimated. This can be conveniently done by weighing the package. After the package has been weighed or the volume otherwise measured, a change is made in the extent to which the inside of the tube is spread to allow for errors in the selected package weight. In this rnanne rthe volume and weight of the package can be accurately and reliably controlled as the packages are formed.

It is apparent that many modifications and variations of this invention as hereinbefore set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of example only and the invention is limited only by the terms of the appended claims.

I claim:

I. A package forming machine for producing a package from a flexible sheet material comprising a means for continuously forming the sheet material into a tube, having adjacent edges, a draw means for engaging the tube to draw the tube past the said forming means, a spreading element operatively associated with the tube forming means, a means for changing the radial size of the spreading element so as to change the diameter of the tube and a sealing means for securing together the adjacent edges of the tube.

2. A forming apparatus for producing a package from a flexible sheet mate-rial including a means for forming the sheet material into the form of a tube with overlapping edges, a draw means for engaging the tube to draw the tube past the said forming means, the combination of a spreading element mounted on the apparatus and operatively associated with the tube forming means, a means for changing the radial size of the spreading element so as to change the diameter of the tube correspondingly and a sealing means for securing together the overlapped edges of the tube.

3. A package forming and filling machine for producing filled packages from a flexible sheet material comprising a means for forming the sheet material into a tube, having overlapped edges, a drarwndown means engaging the tube to draw the tube past the said forming means, a circular spreading element mounted on the machine to contact the inside surface of the tube and a means for changing the radial size of the spreading element so as to change the diameter of the tube correspondingly, a sealing means for securing together the overlapped edges of the tube, a means for filling the tube and a means for cutting the tube into sections and for closing the ends of the cut sections.

4. A package forming machine comprising in combination a means for forming said flexible sheet material into a tube with the edges of the tube being positioned adjacent one another, a means for continuously passing the tube through the forming means, an extensible resilient forming element mounted within the tube and adapted to engage the inward surface of the tube, a member mounted upon the forming means for movement relative to the forming means and the resilient element, said memher being positioned within the tube adjacent to the extensible resilient element and in contact therewith, the relative movement between the member and the extensible resilient element being adapted to expand the extensible resilient element against the tube to thereby increase the diameter of the tube and a sealing means for securing the adjacent edges of the tube to each other in the position taken by the edges after the edges have passed over the extensible resilient element.

5. A package forming machine comprising in combination a means for continuously forming said flexible sheet material into a tube, with the edges of the tube being positioned in overlapping relationship, a means for continuously passing the tube through the forming means, an extensible resilient substantially circular spreading element member mounted within the tube and adapted to engage the inward edges of the tube and a ramp member mounted for movement relative to the resilient member and being positioned within the tube in contact with the spreading element and in contact therewith, relative movement between the ramp member and the extensible resilient member being adapted to expand the extensible resilient member against the tube to thereby increase the diameter of the tube and a sealing means for securing the overlapping edges of the tube to each other in a position taken after the overlapping edges have passed over the extensible resilient element.

6. A package forming machine comprising in combination a means for forming flexible sheet material into a tube with the edges of the tube being positioned in overlapping relationship, a means for continuously passing the tube through the forming means, an extensible resilient forming ring mounted within the tube and adapted to engage the inward edges of the tube, a member having an inclined surface, said member being mounted upon the forming means for movement relative to the resiilent forming ring within the tube with said surface in contact with the ring, relative movement between the surface and the extensible resilient ring being adapted to expand the extensible resilient ring against the tube to thereby increase the diameter of the tube and a sealing means for securing the overlapping edges of the tube to each other in a position taken after the edges have passed over the extensible resilient ring.

7. A package filling and forming apparatus for producing packages filled with a plate-like material from flexible sheet material comprising in combination a supporting framework, an extrusion nozzle mounted on the supporting framework, a pump means for forcing said pastelike material into said extrusion nozzle, a guide for forming said flexible sheet material into a tube around the extrusion nozzle, an elongated member extending longitudinally of the extrusion nozzle and mounted for movement longitudinally thereof, a spreading element mounted adjacent to the outside surface of the extrusion nozzle, an inclined surface on the lower end of the elongated member, said surface being positioned in abutting relationship with the spreading element whereby the movement of the elongated member longitudinally of the extrusion nozzle is adapted to move at least portions of the spreading element radially outward against the tube formed from the flexible sheet material to thereby increase the diameter of the tube.

8. The apparatus according to claim 7 wherein the spreading element comprises a circular helical spring mounted concentrically around the outside of the extrusion nozzle.

9. The apparatus according to claim 7 wherein the elongated member comprises a hollow cylindrical mandrel and wherein said surface comprises a circular, beveled, conical surface afhxed to one end of the mandrel and in contact with the spring whereby movement of the mandrel longitudinally of the extrusion nozzle is adapted to change the radial position of the outward edge of the spring relative to the center of the extrusion nozzle.

No references cited.

GRANVILLE Y. CUSTER, JR., Primary Examiner. 

1. A PACKAGE FORMING MACHINE FOR PRODUCING A PACKAGE FROM A FLEXIBLE SHEET MATERIAL COMPRISING A MEANS FOR CONTINUOUSLY FORMING THE SHEET MATERIAL INTO A TUBE, HAVING ADJACENT EDGES, A DRAW MEANS FOR ENGAGING THE TUBE TO DRAW THE TUBE PAST THE SAID FORMING MEANS, A SPREADING ELEMENT OPERATIVELY ASSOCIATED WITH THE TUBE FORMING MEANS, A MEANS FOR CHANGING THE RADIAL SIZE OF THE SPREADING ELEMENT SO AS TO CHANGE THE DIAMETER OF THE TUBE AND A SEALING MEANS FOR SECURING TOGETHER THE ADJACENT EDGES OF THE TUBE. 